Michael Phelps makes a hilariously unfazed face as an opponent danced in front of him before a race

Michael Phelps advanced to the 200m butterfly Olympic final on Monday night from Rio, but the real drama of the evening came in the dressing room during a rare face-off between Phelps and South African swimmer Chad Le Clos.

Le Clos, remember, narrowly beat Phelps for the gold medal in the same event at the London Olympics in 2012. As the two waited in the dressing room prior to their semifinal on Monday night, LeClos started shadow-boxing, jumping in place, and making a small scene.

Phelps, sitting right next to him, gave him an absolute death stare.

NBC

Phelps certainly did not approve of Le Clos' routine. He looked straight-up mad, and at one point even seemed to roll his eyes.